chore: remove central.budget re-export shim

The shim's implementation lived at notifications.formatters._budget from
the start; central.budget was only a 9-line re-export kept around for
import-path compatibility. Point every importer directly at the real
module and delete the shim:

- notifications/renderers/composer.py: lazy import inside a function
- central/wfigs_handler.py, central/satpass_handler.py: import line only
- tests/test_fire_refactor.py, test_nws_refactor.py, test_firms_refactor.py:
  import line only, no behavior change

test_budget_shim.py existed solely to assert identity-equality between
the shim and the real module; with the shim gone there is nothing left
for it to test, so it is deleted too.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

work/meshai/central/budget.py

@@ -1,9 +0,0 @@
-"""Re-export shim — implementation has moved to meshai.notifications.formatters._budget.
-
-Every existing ``from meshai.central.budget import budget_for, fit_to_budget``
-import continues to work unchanged.  This shim is the sole consumer of the
-canonical implementation; update the implementation there, not here.
-"""
-from meshai.notifications.formatters._budget import budget_for, fit_to_budget
-
-__all__ = ["budget_for", "fit_to_budget"]

work/meshai/central/satpass_handler.py

@@ -43,7 +43,7 @@ from typing import Any, Optional
 from zoneinfo import ZoneInfo
 
 from meshai.adapter_config import adapter_config
-from meshai.central.budget import budget_for, fit_to_budget
+from meshai.notifications.formatters._budget import budget_for, fit_to_budget
 from meshai.persistence import get_db
 
 logger = logging.getLogger(__name__)

work/meshai/central/wfigs_handler.py

@@ -29,7 +29,7 @@ inside that connection's autocommit mode.
 
 from __future__ import annotations
 from meshai.adapter_config import adapter_config
-from meshai.central.budget import budget_for, fit_to_budget
+from meshai.notifications.formatters._budget import budget_for, fit_to_budget
 
 import logging
 import time

work/meshai/notifications/renderers/composer.py

@@ -309,7 +309,7 @@ def _resolve_budget(event: Event) -> int:
     src = (getattr(event, "source", "") or "").strip()
     if src:
         try:
-            from meshai.central.budget import budget_for
+            from meshai.notifications.formatters._budget import budget_for
             return budget_for(src)
         except Exception:
             pass

work/tests/test_budget_shim.py

@@ -1,35 +0,0 @@
-"""Phase-0: verify the budget.py re-export shim is identity-equal to the impl.
-
-Both import paths must resolve to the SAME function objects so any runtime
-patching (e.g. in existing tests) affects both paths simultaneously.
-"""
-
-import meshai.central.budget as _shim
-import meshai.notifications.formatters._budget as _impl
-
-
-def test_budget_for_is_same_object():
-    assert _shim.budget_for is _impl.budget_for, (
-        "meshai.central.budget.budget_for must be the same object as "
-        "meshai.notifications.formatters._budget.budget_for"
-    )
-
-
-def test_fit_to_budget_is_same_object():
-    assert _shim.fit_to_budget is _impl.fit_to_budget, (
-        "meshai.central.budget.fit_to_budget must be the same object as "
-        "meshai.notifications.formatters._budget.fit_to_budget"
-    )
-
-
-def test_shim_imports_work():
-    """Smoke: the public names are importable from the legacy path."""
-    from meshai.central.budget import budget_for, fit_to_budget  # noqa: F401
-    assert callable(budget_for)
-    assert callable(fit_to_budget)
-
-
-def test_budget_for_returns_default_without_adapter_config(monkeypatch):
-    """budget_for falls back to 140 when the adapter key is absent."""
-    val = _shim.budget_for("__no_such_adapter__")
-    assert val == 140

work/tests/test_fire_refactor.py

@@ -22,7 +22,7 @@ from __future__ import annotations
 import pytest
 
 from meshai import central_normalizer as cn
-from meshai.central.budget import budget_for
+from meshai.notifications.formatters._budget import budget_for
 from meshai.central.wfigs_handler import (
     _build_canonical,
     _render as _wfigs_render,

work/tests/test_firms_refactor.py

@@ -31,7 +31,7 @@ import uuid
 
 import pytest
 
-from meshai.central.budget import budget_for
+from meshai.notifications.formatters._budget import budget_for
 from meshai.notifications.formatters.fire import format as fire_format
 from meshai.notifications.formatters.firms import format as firms_format
 from meshai.notifications.gating.firms import decide as firms_decide

work/tests/test_nws_refactor.py

@@ -38,7 +38,7 @@ from datetime import datetime
 
 import pytest
 
-from meshai.central.budget import budget_for
+from meshai.notifications.formatters._budget import budget_for
 from meshai.notifications.formatters.nws import format as nws_format
 from meshai.notifications.gating.nws import decide as nws_decide
 from meshai.persistence import close_thread_connection, init_db